1. Field of the Invention
The present invention relates to Compact Peripheral Component Interconnect (xe2x80x9cCPCIxe2x80x9d) computer systems. More particularly, the present invention relates to a method and apparatus for providing a CPCI computer system in which front side access is provided for both active and passive CPCI cards.
2. Description of Related Art
CPCI is a high performance industrial bus based on the standard PCI electrical specification in rugged 3U or 6U Eurocard packaging. CPCI is intended for application in telecommunications, computer telephony, real-time machine control, industrial automation, real-time data acquisition, instrumentation, military systems or any other application requiring high speed computing, modular and robust packaging design, and long term manufacturer support. Because of its extremely high speed and bandwidth, the CPCI bus is particularly well suited for many high-speed data communication applications such as servers, routers, converters, and switches.
Compared to standard desktop PCI, CPCI supports twice as many PCI slots (8 versus 4) and offers a packaging scheme that is much better suited for use in industrial applications. Conventional CPCI cards are designed for front loading and removal from a card cage. The cards are firmly held in position by their connector, card guides on both sides, and a faceplate that solidly screws into the card cage. Cards are mounted vertically allowing for natural or forced air convection for cooling. Also, the pin-and-socket connector of the CPCI card is significantly more reliable and has better shock and vibration characteristics than the card edge connector of the standard PCI cards.
Conventional CPCI defines a backplane environment that is limited to eight slots.
More specifically, the bus segment of the conventional CPCI system is limited to eight slots, which includes a system slot and peripheral slots. According to conventional standards, the system slot provides clocking, arbitration, configuration, and interrupt processing for up to seven peripheral slots.
Conventional CPCI systems are further defined by the insertion of front side xe2x80x9cactivexe2x80x9d daughter cards (xe2x80x9cfront cardsxe2x80x9d) comprising various signals that xe2x80x9cpass-throughxe2x80x9d relevant interconnect signals and mate with rear side xe2x80x9cpassivexe2x80x9d input/output (I/O) card(s) (xe2x80x9crear transition cardsxe2x80x9d). As is commonly practiced in the art, rear transition cards are designed to require minimal maintenance relative to front active cards. Consequently, it has also become common practice to physically place the front of these backplanes in a location relatively more accessible than the rear of the backplane (e.g., having the rear side of the backplane facing a wall as opposed to the front side). In several applications (e.g., telephony technology), however, CPCI systems are rapidly increasing in size and complexity. As a result, conventional CPCI architecture has become increasingly problematic whenever rear transition cards require maintenance or replacement in these types of applications.
Accordingly, there is a need in the art for a CPCI computer system designed to provide improved accessibility to passive transition cards. In particular, it would be advantageous to provide a CPCI computer system in which front side access is provided for both active and passive CPCI cards.
The present invention relates to a system and apparatus for providing a compact peripheral component interconnect (CPCI) computer system with exclusive front card access for both active and passive CPCI cards. This system is further comprised of an active backplane with a front and rear side, a plurality of slots each comprising of at least one connector and each of these connectors having a column and row arrangement of connector-pins, wherein individual ones of these connector-pins correspond to selected pairs of adjacent slots, and wherein selected adjacent slot pairs are reserved for particular pairs of CPCI cards comprising a single active card and a single passive card, an active card and its corresponding passive card.
A more complete understanding of the front access only CPCI computer system will be afforded to those skilled in the art, as well as a realization of additional advantages and objects thereof, by a consideration of the following detailed description of the preferred embodiment. Reference will be made to the appended sheets of drawings which will first be described briefly.